Ventilator



FIG. 1 is a top plan view of a ventilator showing my new design;

FIG. 2 is an elevational view taken from one side thereof, the opposite side being the same as the side shown;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a ventilator, as shown and described. 